266 SOCIAL LIFE IN THE INSECT WORLD 



the work of the new-born larva ; a sub-epidermic tunnel 

 along which the grub works its way, while seeking a 

 point from which it can escape into a pea. This point 

 once attained, the larva, which is scarcely a twenty-fifth 

 of an inch in length, and is white with a black head, 

 perforates the envelope and plunges into the capacious 

 hollow of the pod. 



It has reached the peas and crawls upon the nearest. 

 I have observed it with the magnifier. Having explored 

 the green globe, its new world, it begins to sink a well 

 perpendicularly into the sphere. I have often seen it 

 half-way in, wriggling its tail in the effort to work the 

 quicker. In a short time the grub disappears and is at 

 home. The point of entry, minute, but always easily 

 recognisable by its brown coloration on the pale green 

 background of the pea, has no fixed location ; it may be 

 at almost any point on the surface of the pea, but an 

 exception is usually made of the lower half ; that is, the 

 hemisphere whose pole is formed by the supporting 

 stem. 



It is precisely in this portion that the germ is found, 

 which will not be eaten by the larva, and will remain 

 capable of developing into a plant, in spite of the large 

 aperture made by the emergence of the adult insect. 

 Why is this particular portion left untouched ? What 

 are the motives that safeguard the germ ? 



It goes without saying that the Bruchus is not con- 

 sidering the gardener. The pea is meant for it and for 

 no one else. In refusing the few bites that would lead to 

 the death of the seed, it has no intention of limiting its 

 destruction. It abstains from other motives. 



Let us remark that the peas touch laterally, and are 



